Sprinkler base



FIG. 1 is a perspective view of a sprinkler base showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a diagram showing the operation status of the sprinkler mounted to the base thereof.

The broken line showing is included for the purpose of illustrating and forms no part of the claimed design. 

The ornamental design for the “sprinkler base,” as shown and described. 